The present invention relates generally to air filters employed in food, drug and beverage production processes, and more particularly, to an apparatus for testing the integrity of air filters during a production process.
Air filter integrity is critical in many production environments. Air filter testing is normally performed off-line. By waiting to do off-line tests there is a risk of air filter integrity failure during the production process which may result in unnecessary downtime and waste of product. The present invention works while a production process is ongoing and thus the system is referred to as an "on-line" air filter integrity test system. The present invention uses a single test unit and several programmable control valves with customized software to perform predetermined programmable air filter integrity tests while a production system is on-line. The software enables the system to be programmed to stand-by during steam/hydrogen peroxide sterilization by sensing temperature and moisture in the system and to operate on-line after sterilization, to provide an alarm upon sensing a prespecified criteria and to check multiple air filter systems sequentially or individually, either in automatic or manual mode during production, without loss of sterility of the production system.
The most common method of testing air filter integrity is to remove the air filters while the production system is off-line. The entire air filter housing and assembly may be removed from the system and tested. This conventional method suffers from several disadvantages. First, it takes a significant amount of time to manually remove the air filters from the system for testing. Secondly, damage can occur to the air filter apparatus when it is being manually handled. Third, the air filters are sometimes not replaced properly when being re-installed. Fourth, the off-line testing has traditionally been done at predetermined time intervals which can, and does, result in a failure of air filters during the production process which leads to wasted product and more down time.
The present invention is especially useful on aseptic fillers for food, drug, and beverage production systems, but would also work well in non-aseptic environments. The present invention may also be employed with sterile air supply units or systems requiring automatic on-line air filter integrity monitoring and control. Air filter integrity is critical in aseptic processing for continuously supplying sterile air necessary for an aseptic processing system. The present invention significantly reduces the risk of wasted product caused by air filter integrity failure during the production process. The present invention is quick, accurate and reliable in detecting the cleanliness of the filtered air supplied to an aseptic processing system. The present invention is versatile for applications to automate and control aseptic processing units or systems. The present invention offers significant cost savings for multiple air filter system integrity detection or multiple point contamination monitoring. The present invention includes programmable operation logic and flexible control features. It may remain independent of, or be combined with, the main operating control system, and it offers contamination free testing of the processing system.
The present invention comprises a particle counter in connection with a computer which sequentially detects contaminant levels in the air located in outlet lines from respective air filters in a production environment. Sample lines are connected to the outlets of each air filter in the production system and the computer may be programmed to test the output of each air filter sequentially and preferably continuously during a production process. By placing valves in association with each of the air filters, individual air filters may be isolated for testing. If the air which has passed through an air filter is determined to exceed the predetermined allowable contaminant levels, the testing system includes means for indicating that acceptable contaminant levels have been exceeded and the production process should be stopped until the defective air filter has been replaced.